Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Updated Clinical Practice Guideline From the Academy of Neurologic Physical Therapy of the American Physical Therapy Association.

BACKGROUND: Uncompensated vestibular hypofunction can result in symptoms of dizziness, imbalance, and/or oscillopsia, gaze and gait instability, and impaired navigation and spatial orientation; thus, may negatively impact an individual's quality of life, ability to perform activities of daily living, drive, and work. It is estimated that one-third of adults in the United States have vestibular dysfunction and the incidence increases with age. There is strong evidence supporting vestibular physical therapy for reducing symptoms, improving gaze and postural stability, and improving function in individuals with vestibular hypofunction. The purpose of this revised clinical practice guideline is to improve quality of care and outcomes for individuals with acute, subacute, and chronic unilateral and bilateral vestibular hypofunction by providing evidence-based recommendations regarding appropriate exercises. METHODS: These guidelines are a revision of the 2016 guidelines and involved a systematic review of the literature published since 2015 through June 2020 across 6 databases. Article types included meta-analyses, systematic reviews, randomized controlled trials, cohort studies, case-control series, and case series for human subjects, published in English. Sixty-seven articles were identified as relevant to this clinical practice guideline and critically appraised for level of evidence. RESULTS: Based on strong evidence, clinicians should offer vestibular rehabilitation to adults with unilateral and bilateral vestibular hypofunction who present with impairments, activity limitations, and participation restrictions related to the vestibular deficit. Based on strong evidence and a preponderance of harm over benefit, clinicians should not include voluntary saccadic or smooth-pursuit eye movements in isolation (ie, without head movement) to promote gaze stability. Based on moderate to strong evidence, clinicians may offer specific exercise techniques to target identified activity limitations and participation restrictions, including virtual reality or augmented sensory feedback. Based on strong evidence and in consideration of patient preference, clinicians should offer supervised vestibular rehabilitation. Based on moderate to weak evidence, clinicians may prescribe weekly clinic visits plus a home exercise program of gaze stabilization exercises consisting of a minimum of: (1) 3 times per day for a total of at least 12 minutes daily for individuals with acute/subacute unilateral vestibular hypofunction; (2) 3 to 5 times per day for a total of at least 20 minutes daily for 4 to 6 weeks for individuals with chronic unilateral vestibular hypofunction; (3) 3 to 5 times per day for a total of 20 to 40 minutes daily for approximately 5 to 7 weeks for individuals with bilateral vestibular hypofunction. Based on moderate evidence, clinicians may prescribe static and dynamic balance exercises for a minimum of 20 minutes daily for at least 4 to 6 weeks for individuals with chronic unilateral vestibular hypofunction and, based on expert opinion, for a minimum of 6 to 9 weeks for individuals with bilateral vestibular hypofunction. Based on moderate evidence, clinicians may use achievement of primary goals, resolution of symptoms, normalized balance and vestibular function, or plateau in progress as reasons for stopping therapy. Based on moderate to strong evidence, clinicians may evaluate factors, including time from onset of symptoms, comorbidities, cognitive function, and use of medication that could modify rehabilitation outcomes. DISCUSSION: Recent evidence supports the original recommendations from the 2016 guidelines. There is strong evidence that vestibular physical therapy provides a clear and substantial benefit to individuals with unilateral and bilateral vestibular hypofunction. LIMITATIONS: The focus of the guideline was on peripheral vestibular hypofunction; thus, the recommendations of the guideline may not apply to individuals with central vestibular disorders. One criterion for study inclusion was that vestibular hypofunction was determined based on objective vestibular function tests. This guideline may not apply to individuals who report symptoms of dizziness, imbalance, and/or oscillopsia without a diagnosis of vestibular hypofunction. DISCLAIMER: These recommendations are intended as a guide to optimize rehabilitation outcomes for individuals undergoing vestibular physical therapy. The contents of this guideline were developed with support from the American Physical Therapy Association and the Academy of Neurologic Physical Therapy using a rigorous review process. The authors declared no conflict of interest and maintained editorial independence.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A369).

Utility of a Postural Stability/Perceptual Inhibition Dual Task for Identifying Concussion in Adolescents.

CONTEXT: Research in the area of dual-task paradigms to assess sport-related concussion (SRC) status is growing, but additional assessment of this paradigm in adolescents is warranted. DESIGN: This case-control study compared 49 adolescent athletes aged 12-20 years with diagnosed SRC to 49 age- and sex-matched controls on visual-spatial discrimination and perceptual inhibition (PIT) reaction time tasks performed while balancing on floor/foam pad conditions. METHODS: The SRC group completed measures at a single time point between 1 and 10 days postinjury. Primary outcomes were dual-task reaction time, accuracy, and sway. General linear models evaluated differences between groups (P < .05). Logistic regression identified predictors of concussion from outcomes. Area under the curve evaluated discriminative ability of identifying SRC. RESULTS: Results supported significantly higher anterior-posterior (AP) sway values in concussed participants for visual-spatial discrimination and PIT when balancing on the floor (P = .03) and foam pad (P = .03), as well as mediolateral sway values on the floor during visual-spatial discrimination (P = .01). Logistic regression analysis (R2 = .15; P = .001) of all dual-task outcomes identified AP postural sway during the PIT foam dual task as the only significant predictor of concussed status (ß = -2.4; P = .004). Total symptoms (area under the curve = 0.87; P < .001) and AP postural sway on foam (area under the curve = 0.70; P = .001) differentiated concussed from controls. CONCLUSION: The AP postural sway on foam during a postural stability/PIT dual task can identify concussion in adolescents between 1 and 10 days from injury.

Vestibular Rehabilitation and Factors That Can Affect Outcome.

This review will discuss the developmental, environmental, medical, psychological, visual, and other sensory-related factors that affect recovery after vestibular dysfunction. A general overview of the evidence for vestibular rehabilitation for patients with peripheral and central vestibular disorders is provided. Recent findings suggest that age, physical activity, certain congenital disorders, length of symptoms, musculoskeletal, visual and neuromuscular comorbidities, cognition, sleep, and medications are all factors that influence the effectiveness and outcome of vestibular rehabilitation. Psychological factors that also affect outcome include anxiety, depression, fear of movement, and fear of falling. Recovery in patients with vestibular disorders may be enhanced if the practitioner recognizes and attempts to remediate modifiable factors.

Changes in Cortical Activation During Dual-Task Walking in Individuals With and Without Visual Vertigo.

BACKGROUND AND PURPOSE: Persons with vestibular disorders are known to have slower gait speed with greater imbalance and veering during dual-task walking than healthy individuals, but the cerebral mechanisms are unknown. The purpose of this study was to determine whether individuals with visual vertigo (VV) have different cerebral activation during dual-task walking compared with control subjects. METHODS: Fourteen individuals with VV and 14 healthy controls (CON) were included (mean 39 years old, 85% women). A cross-sectional experimental study consisting of 4 combinations of 2 surfaces (even and uneven) and 2 task conditions (single- and dual-task) was performed. Participants walked over an even (level flooring) or uneven (wood prisms underneath carpeting) surface, either quietly or while reciting every other letter of the alphabet. Changes in cerebral activation over the bilateral prefrontal cortices were recorded using functional near-infrared spectroscopy during 4 task conditions relative to quiet standing. Gait speed and cognitive performance were recorded. RESULTS: There were no between-group differences in cognitive performance. Both groups slowed when walking on an uneven surface or performing a dual-task; participants in the VV group walked more slowly than those in the CON group in all conditions. Participants with VV had decreased cerebral activation in the bilateral prefrontal regions in comparison to CON participants in all conditions. DISCUSSION AND CONCLUSIONS: Participants with VV had lower prefrontal cortex activation than CON participants during dual-task walking. Lower cortical activity in those with VV may be due to shifted attention away from the cognitive task to prioritize maintenance of dynamic balance.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A303).

Inhibition and decision-processing speed are associated with performance on dynamic posturography in older adults.

Changes in cognition due to age have been associated with falls and reduced standing postural control. Sensory integration is one component of postural control that may be influenced by certain aspects of cognitive functioning. This study investigated associations between measures of cognitive function and sensory integration capabilities for healthy young and older adults. Dynamic posturography was performed using the Equitest Sensory Organization Test (SOT) protocol to evaluate sensory integration during standing using sway-referencing of the platform and/or visual scene to alter somatosensory and visual inputs. The Equilibrium Score was used as a measure of sway. Cognitive testing examined aspects of cognitive function that have been associated with falls in older adults. A correlational analysis investigated associations between the cognitive measures and postural sway during the altered sensory conditions of the SOT. For older subjects only, slower decision-processing speed was associated with increased sway during SOT conditions whenever somatosensation was altered. Reduced perceptual inhibition was associated with increased sway whenever somatosensation was intact, and particularly when vision was altered in the presence of somatosensation. Visuospatial construct ability was associated with sway only when the eyes were closed during altered somatosensation. Task-switching was associated with sway only when vision and somatosensation were intact. With increased age, deficits in decision speed and inhibition appear associated with the sensory integration crucial for balance maintenance. Associations are modulated by the availability of somatosensation and vision. These associations define situations and individual differences in aspects of cognition that may relate to situational loss of balance in older adults.

Reliability of Postural Sway Measures of Standing Balance Tasks.

The reliability of balance exercises performance in experimental and clinical studies has typically been confined to a small set of exercises. In order to advance the field of assessing balance exercise intensity, establishing the reliability of performance during a more diverse array of exercises should be undertaken. The purpose of this study was to investigate the test-retest reliability of postural sway produced during performance of 24 different balance tasks, and to evaluate the reliability of different measures of postural sway. Sixty-two healthy subjects between the ages of 18 and 85 years of age (50% female, mean age 55 ± 20 years) participated. Subjects were tested during two visits one week apart and performed two sets of the 24 randomized standing tasks per visit. The tasks consisted of combinations of the following factors: surface (firm and foam), vision (eyes open and eyes closed), stance (feet apart and semi-tandem), and head movement (no movement, yaw, and pitch). Angular position displacement, angular velocity, and linear acceleration postural sway in the pitch and roll planes was recorded via an inertial measurement unit. The postural sway measures demonstrated at fair to good test-retest reliability with few exceptions, and angular velocity measures demonstrated the greatest reliability. The between-visit reliability of two averaged trials was excellent for most tasks. The study indicates that performance of most balance tasks used as part of balance rehabilitation is reliable, and quantitative assessment could be used to document change.

Perceptual Inhibition Associated with Sensory Integration for Balance in Older Adults.

AIMS: Inhibition associated with perception has been implicated in sensory integration processes for balance when sensory conflict occurs. The current study examines the associations of three measures of inhibition (perceptual inhibition, motor inhibition, and Stroop interference) with standing balance under sensory conflict conditions in younger and older adults. METHODS: Perceptual inhibition, motor inhibition, and Stroop interference were measured in younger and older subjects. Standing balance under conditions of sensory conflict was evaluated using a modified dynamic posturography protocol. Correlative analysis was performed to examine the associations between the inhibition measures and sway. RESULTS: In older adults only, perceptual inhibition was correlated with sway when sensory conflict was present. Stroop interference and motor inhibition were not significantly correlated with sway under any posturography conditions. CONCLUSION: Measures of perceptual inhibition are associated with reduced sensory integration capability for balance during sensory conflict conditions in older adults.

Correction to: Functional near-infrared spectroscopy (fNIRS) brain imaging of multi-sensory integration during computerized dynamic posturography in middle-aged and older adults.

In the original publication, Figs. 2 and 3 are not placed in the correct order. Figure 2 should be replaced by Fig. 3 and Fig. 3 should be replaced by Fig. 2.

Beat-to-beat control of human optokinetic nystagmus slow phase durations.

This study provides the first clear evidence that the generation of optokinetic nystagmus fast phases (FPs) is a decision process that is influenced by performance of a concurrent disjunctive reaction time task (DRT). Ten subjects performed an auditory DRT during constant velocity optokinetic stimulation. Eye movements were measured in three dimensions with a magnetic search coil. Slow phase (SP) durations were defined as the interval between FPs. There were three main findings. Firstly, human optokinetic nystagmus SP durations are consistent with a model of a Gaussian basic interval generator (a type of biological clock), such that FPs can be triggered randomly at the end of a clock cycle (mean duration: 200-250 ms). Kolmogorov-Smirnov tests could not reject the modeled cumulative distribution for any data trials. Secondly, the FP need not be triggered at the end of a clock cycle, so that individual SP durations represent single or multiple clock cycles. Thirdly, the probability of generating a FP at the end of each interval generator cycle decreases significantly during performance of a DRT. These findings indicate that the alternation between SPs and FPs of optokinetic nystagmus is not purely reflexive. Rather, the triggering of the next FP is postponed more frequently if a recently presented DRT trial is pending action when the timing cycle expires. Hence, optokinetic nystagmus FPs show dual-task interference in a manner usually attributed to voluntary movements, including saccades. NEW & NOTEWORTHY: This study provides the first clear evidence that the generation of optokinetic nystagmus (OKN) fast phases is a decision process that is influenced by performance of a concurrent disjunctive reaction time task (DRT). The slow phase (SP) durations are consistent with a Gaussian basic interval generator and multiple interval SP durations occur more frequently in the presence of the DRT. Hence, OKN shows dual-task interference in a manner observed in voluntary movements, such as saccades.

Sensory and motoric influences on attention dynamics during standing balance recovery in young and older adults.

This study investigated the impact of attention on the sensory and motor actions during postural recovery from underfoot perturbations in young and older adults. A dual-task paradigm was used involving disjunctive and choice reaction time (RT) tasks to auditory and visual stimuli at different delays from the onset of two types of platform perturbations (rotations and translations). The RTs were increased prior to the perturbation (preparation phase) and during the immediate recovery response (response initiation) in young and older adults, but this interference dissipated rapidly after the perturbation response was initiated (<220 ms). The sensory modality of the RT task impacted the results with interference being greater for the auditory task compared to the visual task. As motor complexity of the RT task increased (disjunctive versus choice) there was greater interference from the perturbation. Finally, increasing the complexity of the postural perturbation by mixing the rotational and translational perturbations together increased interference for the auditory RT tasks, but did not affect the visual RT responses. These results suggest that sensory and motoric components of postural control are under the influence of different dynamic attentional processes.

Functional near-infrared spectroscopy (fNIRS) brain imaging of multi-sensory integration during computerized dynamic posturography in middle-aged and older adults.

Studies suggest that aging affects the sensory re-weighting process, but the neuroimaging evidence is minimal. Functional Near-Infrared Spectroscopy (fNIRS) is a novel neuroimaging tool that can detect brain activities during dynamic movement condition. In this study, fNIRS was used to investigate the hemodynamic changes in the frontal-lateral, temporal-parietal, and occipital regions of interest (ROIs) during four sensory integration conditions that manipulated visual and somatosensory feedback in 15 middle-aged and 15 older adults. The results showed that the temporal-parietal ROI was activated more when somatosensory and visual information were absent in both groups, which indicated the sole use of vestibular input for maintaining balance. While both older adults and middle-aged adults had greater activity in most brain ROIs during changes in the sensory conditions, the older adults had greater increases in the occipital ROI and frontal-lateral ROIs. These findings suggest a cortical component to sensory re-weighting that is more distributed and requires greater attention in older adults.

A Quality Improvement Project in Balance and Vestibular Rehabilitation and Its Effect on Clinical Outcomes.

BACKGROUND AND PURPOSE: Unwarranted variation in practice is among the principal contributors of suboptimal outcomes in health care. This variation can be minimized via quality improvement initiatives. However, quality improvement projects focus mostly on assessing processes, and less attention is given to the effect of the variation on clinical outcomes. An effective implementation of a clinical treatment algorithm (CTA) could improve care for individuals with balance and vestibular disorders. The first aim of this quality improvement project was to examine adherence to a CTA developed by physical therapists who treat persons with balance and vestibular disorders. The second aim was to examine the effect of adherence on patient outcomes. METHODS: Twenty-three physical therapists who provided rehabilitation for individuals with balance and vestibular disorders participated in the quality improvement project. All physical therapists worked for the same health care provider, and developed the minimum data set and CTA. The physical therapists were cluster randomized into 2 groups; both groups received educational training and reminders regarding adherence to the CTA. The first group received the training and reminders after an 8-week baseline period (initial group), and the second group (delayed group) after a 12-week baseline period. The prescribed interventions were classified as being adherent or nonadherent to the CTA. Clinical outcomes, including the Activities-Specific Balance Confidence (ABC) scale, Dizziness Handicap Inventory (DHI), and the Global Rating of Change (GRC), were recorded at the initial evaluation and discharge for 454 individual with balance or vestibular disorders. RESULTS: Across the 16-week project, adherence rates improved significantly by 9% and 12% for the initial and delayed groups, respectively (P = 0.008), but there was no difference between groups related to the timing of the educational training and adherence reminders. Clinical outcomes improved for individuals, with balance or vestibular disorders but there was no differences in the change in ABC, DHI, and GRC scores based on whether the interventions were or were not adherent to the CTA. DISCUSSION AND CONCLUSIONS: This quality improvement project was effective in increasing the adherence to the CTA in both groups. Although on average individuals with balance and vestibular disorders showed improvement on the clinical outcomes, there was no additional benefit in the clinical outcome for adherent interventions.Video abstract is available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A125).

Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Evidence-Based Clinical Practice Guideline: FROM THE AMERICAN PHYSICAL THERAPY ASSOCIATION NEUROLOGY SECTION.

BACKGROUND: Uncompensated vestibular hypofunction results in postural instability, visual blurring with head movement, and subjective complaints of dizziness and/or imbalance. We sought to answer the question, "Is vestibular exercise effective at enhancing recovery of function in people with peripheral (unilateral or bilateral) vestibular hypofunction?" METHODS: A systematic review of the literature was performed in 5 databases published after 1985 and 5 additional sources for relevant publications were searched. Article types included meta-analyses, systematic reviews, randomized controlled trials, cohort studies, case control series, and case series for human subjects, published in English. One hundred thirty-five articles were identified as relevant to this clinical practice guideline. RESULTS/DISCUSSION: Based on strong evidence and a preponderance of benefit over harm, clinicians should offer vestibular rehabilitation to persons with unilateral and bilateral vestibular hypofunction with impairments and functional limitations related to the vestibular deficit. Based on strong evidence and a preponderance of harm over benefit, clinicians should not include voluntary saccadic or smooth-pursuit eye movements in isolation (ie, without head movement) as specific exercises for gaze stability. Based on moderate evidence, clinicians may offer specific exercise techniques to target identified impairments or functional limitations. Based on moderate evidence and in consideration of patient preference, clinicians may provide supervised vestibular rehabilitation. Based on expert opinion extrapolated from the evidence, clinicians may prescribe a minimum of 3 times per day for the performance of gaze stability exercises as 1 component of a home exercise program. Based on expert opinion extrapolated from the evidence (range of supervised visits: 2-38 weeks, mean = 10 weeks), clinicians may consider providing adequate supervised vestibular rehabilitation sessions for the patient to understand the goals of the program and how to manage and progress themselves independently. As a general guide, persons without significant comorbidities that affect mobility and with acute or subacute unilateral vestibular hypofunction may need once a week supervised sessions for 2 to 3 weeks; persons with chronic unilateral vestibular hypofunction may need once a week sessions for 4 to 6 weeks; and persons with bilateral vestibular hypofunction may need once a week sessions for 8 to 12 weeks. In addition to supervised sessions, patients are provided a daily home exercise program. DISCLAIMER: These recommendations are intended as a guide for physical therapists and clinicians to optimize rehabilitation outcomes for persons with peripheral vestibular hypofunction undergoing vestibular rehabilitation.Video Abstract available for more insights from the author (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A124).

Relationship Between Cognitive Assessment and Balance Measures in Adolescents Referred for Vestibular Physical Therapy After Concussion.

OBJECTIVE: To examine the relationship between cognitive and balance performance in adolescents with concussion. DESIGN: Retrospective case series. SETTING: Tertiary. PATIENTS: Sixty patients. INTERVENTIONS: Correlation analyses were performed to describe the relationship between symptoms, cognitive measure, and balance measure at the time of initiation of vestibular physical therapy. MAIN OUTCOME MEASURES: Cognitive performance was assessed using the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT). The dizziness and balance function measures included dizziness severity rating, Activities-specific Balance Confidence scale (ABC), Dizziness Handicap Inventory (DHI), Functional Gait Assessment, gait speed, Timed "UP and GO," Five Times Sit to Stand, and Sensory Organization Test (SOT). To account for multiple comparisons, the False Discovery Rate method was used. RESULTS: Performance measures of balance were significantly correlated with cognitive measures. Greater total symptom scores were related to greater impairment in the ABC and DHI (r = 0.35-0.39, P ≤ 0.008) and worse performance in condition 2 of the SOT (r = -0.48, P = 0.004). Among the ImPACT composite scores, lower memory scores were correlated with impaired balance performance measures (r = 0.37-0.59, P ≤ 0.012). Lower visual memory was also correlated with worse ABC scores. CONCLUSIONS: The significant relationships reported between the cognitive performance scores and balance measures may reflect that similar levels of functioning exist across domains in individuals with protracted recovery who receive vestibular physical therapy. CLINICAL RELEVANCE: The weak-to-moderate relationships warrant the continuous use of multiple domains of assessment. A better understanding to the relationships between the domains of functioning after concussion may improve the overall management approach for adolescents with concussion.

The effect of age on postural and cognitive task performance while using vibrotactile feedback.

Vibrotactile feedback (VTF) has been shown to improve balance performance in healthy people and people with vestibular disorders in a single-task experimental condition. It is unclear how age-related changes in balance affect the ability to use VTF and if there are different attentional requirements for old and young adults when using VTF. Twenty younger and 20 older subjects participated in this two-visit study to examine the effect of age, VTF, sensory condition, cognitive task, duration of time, and visit on postural and cognitive performance. Postural performance outcome measures included root mean square of center of pressure (COP) and trunk tilt, and cognitive performance was assessed using the reaction time (RT) from an auditory choice RT task. The results showed that compared with younger adults, older adults had an increase in COP in fixed platform conditions when using VTF, although they were able to reduce COP during sway-referenced platform conditions. Older adults also did not benefit fully from using VTF in their first session. The RTs for the secondary cognitive tasks increased significantly while using the VTF in both younger and older adults. Older adults had a larger increase compared with younger adults, suggesting that greater attentional demands were required in older adults when using VTF information. Future training protocols for VTF should take into consideration the effect of aging.

Postural adjustment errors during lateral step initiation in older and younger adults.

The purpose was to examine age differences and varying levels of step response inhibition on the performance of a voluntary lateral step initiation task. Seventy older adults (70-94 years) and twenty younger adults (21-58 years) performed visually cued step initiation conditions based on direction and spatial location of arrows, ranging from a simple choice reaction time task to a perceptual inhibition task that included incongruous cues about which direction to step (e.g., a left pointing arrow appearing on the right side of a monitor). Evidence of postural adjustment errors and step latencies were recorded from vertical ground reaction forces exerted by the stepping leg. Compared with younger adults, older adults demonstrated greater variability in step behavior, generated more postural adjustment errors during conditions requiring inhibition, and had greater step initiation latencies that increased more than younger adults as the inhibition requirements of the condition became greater. Step task performance was related to clinical balance test performance more than executive function task performance.

Estimating postural control with the balance rehabilitation unit: measurement consistency, accuracy, validity, and comparison with dynamic posturography.

OBJECTIVE: To examine the psychometric properties (test-retest reliability, concurrent validity, construct validity) of the Balance Rehabilitation Unit (BRU) during testing of sensory integration processes in healthy adults and individuals with vestibular disorders. DESIGN: Experimental cross-sectional design. SETTING: Clinic. PARTICIPANTS: Participants (N=90) included 30 subjects with vestibular disorders (age range, 18-85y), 30 young healthy adults (age range, 18-50y), and 30 older healthy adults (age range, 60-85y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were tested twice with the BRU and once with the SMART EquiTest Sensory Organization Test (SOT). The center of pressure (COP) in the anteroposterior direction (COPap) and the COP in the mediolateral direction (COPml) were recorded. The COPap and COPml time series were used to estimate the area and velocity of the COP. RESULTS: The intraclass correlation coefficient of the COP area and velocity measures for the BRU for all subjects was at least .76 in all sensory organization conditions (P<.001). Significant correlations were found between the BRU and the SOT, ranging from .64 to .81 for COP area and from .44 to .76 for COP velocity. The older control group had significantly greater COP area and velocity compared with younger controls for the BRU and the SOT. The COP (area, velocity) was significantly higher for the younger individuals in the vestibular group than the younger controls. CONCLUSIONS: The reliability and validity of COP measurements obtained during testing of the sensory integration processes were demonstrated using the BRU. Future work should examine the responsiveness of these measures when individuals with balance disorders participate in rehabilitation.

Performance of high school adolescents on functional gait and balance measures.

PURPOSE: To describe the performance of high school adolescents during common functional gait and balance measures used in vestibular physical therapy. METHODS: A cross-sectional study of 91 participants determined their performance on the Activities-specific Balance Confidence (ABC) scale, Dynamic Gait Index, Functional Gait Assessment, Timed "Up and Go" (TUG), Five Times Sit to Stand (FTSTS) test, tests of gait speed (GS), and the Balance Error Scoring System. In a subset of this sample, GS, TUG, and the FTSTS were repeated twice to examine test-retest reliability. RESULTS: The measures of GS, TUG, and FTSTS were normally distributed. The Activities-specific Balance Confidence, Dynamic Gait Index, and Functional Gait Assessment exhibited a ceiling effect. The timed measures exhibited moderate to good reliability. CONCLUSIONS: These performance scores may provide end points for discharge from vestibular physical therapy. However, clinicians should be aware of the ceiling effect exhibited by some measures.

The vertical computerized rotational head impulse test.

The computerized rotational head impulse test (crHIT) uses a computer-controlled rotational chair to deliver whole-body rotational impulses to assess the semicircular canals. The crHIT has only been described for horizontal head plane rotations. The purpose of this study was to describe the crHIT for vertical head plane rotations. In this preliminary study, we assessed four patients with surgically confirmed unilateral peripheral vestibular abnormalities and two control subjects. Results indicated that the crHIT was well-tolerated for both horizontal head plane and vertical head plane stimuli. The crHIT successfully assessed each of the six semicircular canals. This study suggests that the crHIT has the potential to become a new laboratory-based vestibular test for both the horizontal and vertical semicircular canals.

Balance strategies for recovery from perturbed overground walking.

Bipedal locomotion is naturally unstable and requires active control. Walking is believed to be primarily stabilized through the selection of foot placements; however, other strategies are available, including regulation of ankle inversion/eversion, ankle push-off, and angular momentum through trunk postural adjustments. The roles of these strategies in maintaining overall stability are often masked by the dominant foot placement strategy. The objectives of this study were to describe how the four strategies are used to respond to medial or lateral ground perturbations during overground walking in healthy individuals and determine reliance on each strategy. Fifteen healthy adults walked with and without perturbations applied to the right foot at heel strike while body kinematics and surface electromyographic activity were measured. Medial perturbations resulted in decreased step width on the first step after the perturbation, increased ankle inversion, increased ankle push-off, and rightward trunk sway. Lateral perturbations resulted in increased step width, decreased ankle inversion, no change in ankle push-off, and leftward trunk sway. EMG activity was consistent with the observed strategies (e.g. increased peroneus longus EMG activity during ankle eversion) with the exception of increased bilateral erector spinae activity for all perturbations. Foot placement was the dominant strategy in response to perturbations, with other strategies showing reduced, yet significant, roles. This work demonstrates that multiple strategies are recruited to improve the balance response in addition to foot placement alone. These results can serve as a reference for future studies of populations with impaired balance to identify potential deficits in strategy selection.